A high interest in scalable video coding in recent years resulted in the currently developing Scalable Video Coding (SVC) standard by JVT (Joint Video Team), by International Organization for Standardization and International Electro-technical Commission (ISO/IEC) Motion Picture Experts Group (MPEG) and International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Video Coding Experts Group (VCEG). The SVC standard will support different scalabilities, including different combinations of temporal, spatial, and quality scalabilities.
Spatial scalability is usually achieved by using a layered approach. A full-resolution original video sequence is spatially down-sampled to a low-resolution video sequence. The full-resolution and low-resolution video sequences go through two parallel video encoders, and are then output as an enhanced layer (high-resolution) coded bit-stream and a base layer (low-resolution) coded bit-stream.
In order to achieve a good coding efficiency, inter-layer prediction is used. Two kinds of inter-layer prediction include inter-layer intra texture prediction and inter-layer motion prediction. The inter-layer intra texture prediction provides an extra option where an upper-layer (or enhanced-layer) intra block can be predicted by a block up-sampled from the reconstructed lower-layer (or base-layer) frames, usually from the corresponding low-resolution reconstructed image block.
A fixed interpolation filter is typically used for the up-sampling process. For example, in the current JSVM (Joined Scalable Verification Model) for the developing SVC standard, a fixed 6-tap filter is used for the up-sampling process. However, the single fixed up-sample interpolation filter may not accurately up-sample different image blocks in the same frame. This limits the effectiveness of the inter-layer prediction process.
The present invention addresses this and other problems associated with the prior art.